The English relative words are words in English used to mark a clause, noun phrase or preposition phrase as relative. The central relative words in English include who, whom, whose, which, why, and while, as shown in the following examples, each of which has the relative clause in bold:
We should celebrate the things which we hold dear. I've been studying hard, which explains my good grades. I finally met Jordan, who had been away. That's the reason why it works.
Most also belong to the set of English interrogative words but function differently as relative words.
The subordinator that is widely regarded as a relative word, though one with different properties from the others.
Semantics Semantically speaking, relative words typically refer to some antecedent in the containing phrase or clause. For example, who within the teacher of mine who likes apples does not question the identity of a person, but rather refers to "the teacher of mine", which in turn denotes some particular person.
Individual words
Who (with whom) primarily refers to persons, although it can also refer to other animate beings. Whose, however, may also refer to non-persons, as in a book whose cover is missing. Which is semantically the most flexible, taking a wide range of antecedents, including propositions, as in I've skipped a lot of classes, which is why I flunked. A clear exception is reference to persons, usually ungrammatical as in *They're the people which I know. This is not absolute, though, as shown by the example I told her Lee was a friend, which he was. Arguably, this use refers to the person's position or the relation, rather than to the person himself. Where refers primarily to locations, but locations broadly conceived, including locations in time (e.g., a time where we have to take that a step forward) and situations (e.g., a situation where we'll need to rethink things). When refers primarily to times and situations. While refers to a period of time. Whence (formal, and somewhat archaic) refers to a place (broadly conceived) and in such sentences as She returned to the house whence she had come has a "from" meaning. Yet examples such as She returned to the house from whence she had come are common. Whither (distinctly archaic) is similar but with a "to" meaning; the contrast with whence is not straightforward in that *to whither is ungrammatical. Why refers primarily to reasons. As a fused relative, and in some nonstandard English dialects more widely, what is general purpose (other than for persons), and how refers to method. More or less archaic and formal compounds of where and a preposition: Whereafter means "after which" (e.g., At the account anniversary, card purchases will revert to 0.5 per cent cashback, until total card spending reaches £15,000 – whereafter 1 per cent cashback will be earned again). Whereat means "at which" (e.g., A Director, notwithstanding his interest, may be counted in the quorum present at any meeting of the Directors whereat he or any other Director is appointed to hold any such office or place of profit under the Company). Whereby means "by which" or "as a result of which" (e.g., This is a new process whereby a work coach will decide what further work search conditions or employment pathways would best support a claimant into work). Wherefrom means "from which" (e.g., You could always count on her to jump up, dance, clap, cry, and uncork the mind-hydrants wherefrom her praise gushed). Wherein means "in which" (e.g., MIT is a phenomenon wherein an insulator becomes capable of conducting electricity when subjected to external factors like changes in the concentration or temperature of an ambient gas). Whereof means "of which" (e.g., The results whereof tell a story of "some win some loss"). Whereon means "on which" (e.g., And yet today the dead earth is revived by sunbeams whereon she hangs her cloak). Whereto means "to which" (e.g., The initiation of contempt proceedings [. . .] was filed [. . .] against Union of India and others, pursuant whereto, 45 days' time was given to contemnor to publish the already approved Byelaws of Cantonment Board, Jammu) Whereupon means "upon which" or "immediately after which" (e.g., A fine home-town debut from the seamer Brydon Carse denied New Zealand any momentum despite a misleadingly run-laden first over from Finn Allen, whereupon a brace of forceful knocks from Dawid Malan and the inevitable Harry Brook allowed Jos Buttler to sit back in the dressing-room with his feet up [. . .]) Wherewith means "with which" (e.g., The key to real social change, they wrote, was "nothing less than vesting in the citizenry the means and the effective power wherewith to criticize, to shape and even to challenge the actions or proposed actions of officials")
All of the words may have singular or plural antecedents. For example, the customer who was cheated/the customers who were cheated.
That differs from the other relative words in that, like other subordinators, it lacks semantic content, referring or otherwise.
Lexical categories and syntactic functions Each relative word also has a syntactic function in a phrase or clause. For example, in the person who arrived, who functions as the subject of the relative clause. Different words have different functions depending on their lexical category and form. For example, while a plain pronoun like who may typically function as a subject or object, its genitive form functions only as a determiner (e.g., the person [whose keys] I found).
Syntax
A relative word occurs within a relative phrase, which appears in clause-initial position. A simple relative phrase consists of a relative word by itself (where within the restaurant where we dined; who within the man who you introduced me to). A complex relative phrase also has other material; it is exemplified by to whom within the man to whom you introduced me, from under which within the rock from under which it had crawled, and whose car within the man whose car you borrowed.
Individual words in relative clauses Who (with its other forms whom and whose) is a pronoun. Whose is the genitive form of who; whom is an accusative form generally limited to careful or formal writing or speech – and thus still commoner with preposition fronting (the employee to whom/?who it was addressed; compare the informal the employee who/%whom it was addressed to, with preposition stranding) – and who is the nominative or (other than formally) the plain form. (Whom is also found as a hypercorrected nominative.) It has been claimed that whose cannot form a simple relative phrase, but The Oxford English Dictionary disagrees, citing, for example, Everything depends on the person whose this administration is. Which is usually a pronoun. It is a determiner in cases like We pause for three weeks, after which time, we will restart. Where, when, and while are prepositions. Why is an adverb. That (often mistakenly called a relative pronoun) is a subordinator. In most contexts, it is omissible; thus I've said all the things (that) I want to say; She's the one (that) you met last week; That's the reason (that) it works. But it is not omissible in Standard English when the relativized element is the subject of the relative clause (*The speech that enraged them was racist), when the subject of the relative clause does not immediately follow that (*The book that during the flight I'd read was most absorbing), or for a supplementary relative (where wh-relatives are anyway far commoner). In some nonstandard dialects, what (a pronoun) and how (an adverb) are used for relative clauses (e.g., !That's the thing what we've been missing, !That's the way how to do it). Whereupon and the other where-plus-preposition compounds are themselves prepositions.
Fused relatives
A fused construction is one in which a word or phrase has two functions at once. A simple type of fused construction (not a relative) is exemplified by any within I didn't notice any: Although a noun phrase (such as any food) is normally headed by a noun, and although any is normally (as in any food) a dependent, within I didn't notice any it heads a noun phrase and thus functions as a fused dependent-head.
Similarly, a fused relative is a noun phrase or preposition phrase (not a clause, but containing one) that is headed by a relative phrase (most commonly by a simple relative phrase, and thus by a relative word alone), and that lacks an antecedent. For example, the fused relative construction who you want within Believe who you want contains the relative phrase who. This has functions within both the NP that contains the relative clause and within the relative clause itself: functions that are fused.
The fused relative is also called a free relative, free relative clause, nominal relative clause, and independent relative clause.
Fused relatives with relative words without -ever A fused relative may be headed by a non-compound word, such as what, by a where+preposition compound, or by a compound with -ever. The three kinds are considered in turn.
Individual non-compound words in fused relatives Who, as in You can believe who you want. But this is archaic with who as the subject in the relative clause: Who steals my purse steals trash was used by Shakespeare, and survives in the expression Can I help who's next? but *You can believe who told you is not used today. Whom, as in You can believe whom you want. Whose, as in You can believe whose version you want. Which, as in You can believe which version you want. Like who, this is not used as the subject in the relative clause: *Use which is handy. When, as in We arrived when it opened. Where, as in My phone wasn't where I'd left it. While, as in We arrived while the band was playing. Whence (rather archaic), as in He returned whence he had come. Whither (distinctly archaic), as in He goes whither he wants. Why, as in Why I resigned was because of the chairman's intransigence. Use in fused relatives of why seems to be limited to pseudo-clefts. What, as in They ate what was offered. Examples with what as a determiner, such as They ate what food was offered and They considered what options were open to them, imply a small quantity or number. How, as in You can dress how you like.
Individual where+preposition words in fused relatives Whereof is widely used, particularly with the verb speak (The mayor, 35, knows whereof she speaks; perhaps best known from the final proposition within Tractatus Logico-Philosophicus in its first English translation: Whereof one cannot speak, thereof one must be silent).
Fused relatives with -ever relative words
Individual -ever words in fused relatives Whoever, as in I cursed whoever had taken it. Whomever, as in I borrow from whomever I can (although this would be a less likely alternative to I borrow from whoever I can). Whoever's, whosever, as in The gang will steal whoever's/whosever car they can. Whichever, as in Buy whichever you like; Buy whichever vase/vases you like. Whenever, as in We go whenever we can. Wherever, as in There were ants wherever we looked. Whatever, as in Buy whatever you like; Buy whatever vase/furniture you like. However, as in However it happened, fix it; However unfair it seems, fix it.
-Soever and -so relative words As relative words, forms ending -soever and -so are old-fashioned variants of the -ever forms. There are whoso(ever), whomso(ever), whichsoever, whensoever and whatso(ever); and the archaisms whencesoever and whithersoever are still occasionally found.
Etymology Ultimately, the English interrogative words (those beginning with wh in addition to the word how), derive from the Proto-Indo-European root kwo- or kwi, the former of which was reflected in Proto-Germanic as χwa- or khwa-, due to Grimm's law.